The integration of wireline and wireless technologies in order to create a common telecommunication network foundation may be referred to as Fixed-Mobile Convergence, FMC, enabling wireline service providers and wireless network operators to use the same physical infrastructure, involving several advantages for the end users, as well as to the service providers and operators. An end user may access wireline and wireless services by the same user terminal, such as a mobile phone or a personal computer, and fixed and mobile services may be offered to the end user in one package.
Within the technical field related to FMC, the policy control architecture plays a vital role, e.g. regarding roaming support and QoS (Quality of Service). Currently, one object of various standardization bodies, such as the 3GPP PCC work-item, the Tispan RACS, the WiMax Forum and the DSL Forum is to agree on a policy control architecture specification, providing a common policy control architecture that is applicable regardless of the access network type. However, several technical problems still need to be solved, the mapping and aligning is far from complete, and the different organizations propose different solutions. The TISPAN and the DSL Forum (DSLF) both have a focus on the fixed access-side, which typically is more influenced by the so called “equal-access” concept. Therefore, they propose a distributed policy control architecture, while the 3GPP (3rd Generation Partnership Project), which relates to radio access networks, prefers a more enclosed policy control architecture, since the mobile/cellular network operators conventionally prefer to give services mainly to their own subscribers. For instance, in DSLF, a PDP (policy decision point) is separated into three parts, an SPC (service policy controller), an NPC (network policy controller) and a UPC (user policy controller), while the policy controlling functions normally are closely coupled in the 3GPP, e.g. according to the PCRF (combined Policy and Charging Rules Functions), which allows rule management of service flow response, gating, QoS and flow based charging independently of the subscriber access technology.
However, in order to allow an end user to move freely from one network to another, of which one of the networks may be a fixed (wireline or wireless) network and the other a radio access network, while the end user at least partly retains his subscribed services, a policy controller in one network must be able to discover its peering policy controller in the other network, and any roaming agreement between the two parties must be detected and retrieved. These objects are not achieved by any existing solution today.
Roaming refers to the extension of a service to a different location than the home location where the service was registered, by means of a roaming agreement. Roaming occurs when a subscriber to one network operator uses the facilities of another operator, such as e.g. when a mobile phone has relocated to another region or another country, where its home operator does not have coverage.
A conventional roaming process when a mobile phone has relocated to a new network involves the following: When the mobile phone is turned on in a new network, or transferred via handover to the new network, the new, visited network detects the phone, notices that it is not registered, and attempts to identify the home network of the mobile phone. If there is no roaming agreement between the home network and the visited network, the mobile phone will be denied services by the visited network. Otherwise, the visited network contacts the home network and requests service information regarding the phone, said information including whether or not the mobile phone is allowed to roam. If the request is successful, the visited network will maintain a temporary subscriber record for the phone, and the home network will update its information to indicate that the phone has relocated to the visited network, allowing a correct routing of information.
The 3GPP provides policy controller discovery between different radio access networks, but in fixed access-networks, e.g. in the fixed broadband world, the principle of equal access leads to a different business model and approach than in the 3GPP. For example, the DSL Forum proposes a policy control architecture composed of a number of separate policy controllers, of which each may belong to a different service provider. However, in the 3GPP, those functions are performed by only one network operator.